Device for driving time works by a high frequency vibrator and means for mounting the device



Dec. 16. 1969 R. SIEFERT 3 1 DEVICE FOR DRIVING TIME WORKS BY A HIGH FREQUENCY VIBHATOR AND MEANS FOR MOUNTING THE DEVICE Filed April 24, 19s? United States Patent Int. Cl. Gt l4c 3/00 US. Cl. 58-43 2 Claims ABSTRACT OF THE DISCLOSURE A stepping wheel on a rotary arbor is mounted on one or both tines of a tuning fork for imparting motion of substantially oscillatory translation of the wheel axis. Fixed-position pawls engage on the stepping wheel so that the translation of the wheel causes a turning thereof. One end of the arbor is carried in a bearing having a substantially fixed position.

BACKGROUND OF THE INVENTION Field of the invention This is a pawled system for utilization of an externally driven tuning fork to power a clockwork.

Description of the prior art There are devices known wherein a pawl on an oscillator acts on a drive wheel bearingly mounted in a fixed location as on a substantially stationary framework, and a detaining pawl for the wheel is similarly mounted in a fixed location. There are serious drawbacks connected with such a construction. The assembly and mounting of such systems and the justifying of the pawls to each other and to the stepping wheel entails a very high labor cost.

Whenever the oscillatory system is disassembled the entire system must be justified anew after reassembly. This justification work can be done only by especially trained expert craftsmen. A further drawback is that a pawl mounted on the oscillator can very easily be damaged during the installation or removal of the oscillator.

SUMMARY OF THE INVENTION An object of the invention is to overcome the cited drawbacks of the prior art. The invention is for a device for driving the works of a time piece powered by a high frequency mechanical oscillator or vibrator and includes a rotary drive arbor for the works carrying a stepping wheel upon which at least one drive pawl engages. One bearing for one end portion of the arbor is mounted on the oscillator and another bearing for the other end, as well as the one or more drive pawls, which may be as blade springs, are mounted on a relatively stationary framework on which the oscillator is also mounted. By such an arrangement it is very easy for almost inexperienced personnel to avoid bending the pawls during assembly or disassembly. Justification of a suitable jig for positioning the pawl blades on the stepping wheel when the dead ends of the blades are in slotted lugs on the frame and then cementing the dead ends in the lugs.

In the invention the stepping wheel on the shaft should be located near the bearing on the oscillator and a takeoff pinion for engaging the work train be near a substantially fixed bearing on the frame. The two bearings should be jewels of olivine or the like. Furthermore the drive ice pawls should engage on the stepped wheel in the path of the oscillation and the detaining pawl be perpendicular to the drive pawl.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic representation of the invention showing a drive pawl and a detaining pawl.

FIG. 2 shows a device like that in FIG. I, but in section and with other working elements;

FIG. 3 is a modification of FIG. 1 showing two drive pawls;

FIG. 4 shows another form of the invention, and

FIG. 5 shows details of the substantially fixed bearing on the frame.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The oscillator is a tuning fork 1 having permanent magnets 2 mounted on the tines 2a and 2b, the magnets being energized by a coil 3 to drive the fork, the fork and coil being mounted on a work plate 4. Tine 2a of the fork is provided with a bearing 7 receiving for rotation one end of an arbor 5 provided with a stepping wheeel 6. The other end of the arbor is mounted for rotating in a substantially fixed bearing 9 in a frame 8, the latter carrying the work plate 4. As shown, the bores 14 and 15 of the bearings 7 and 9 are not purely cylindrical but in the shape of an hour glass for there must be suflicient lateral movement of the arbor especially at its end 16 mounted on tine 2a to enable driving by the pawls described below. The same requirement holds for bore 15 receiving the arbor end 17, each end 16 being of reduced diameter so that the bearings may engage against the lateral mid portion 18 of the arbor during any longitudinal movement of the arbor. Near the fixed bearing 9 is a drive pinion 10 on the arbor for powering a time work partially shown at 11. A drive pawl shown as a blade spring 12 and a similar detaining pawl 13 are mounted on the work plate 4, as by slotted lugs 19, and engage on the wheel 6. The pawls are at about right angles to each other. Instead of one drive and one detaining pawl, two drive pawls 12 and 12 working on opposite sides of the wheel may be used as in FIG. 3.

As set forth in FIG. 4, the oscillatory or vibrated bearing 7 can be mounted on the mid portion of a bowed spring 14 having its respective ends secured to the tines 2a and 2b of the fork. This gives the advantage that the amplitude of bearing movement can be about double that of a tine and the movement is about at right angles to that of the tine. The arrangement in FIG. 4 is furthermore insensitive with respect to disturbances from the gearing or work train and to shock. An additional advantage is that both tines are equally loaded so that tuning of the fork to the intended frequency is facilitated.

I claim:

1. In a clockwork driven by a tuning fork, substantially stationary frame for mounting the fork, said fork having at least one vibratory part thereon, an arbor carrying a stepping wheel fast thereon, two bearings having bores for rotatably mounting the arbor at opposite end portions of the arbor and having bores substantially of the same diameter as said portions, the first bearing being mounted in fixed position on the frame, the second bearing being mounted on said vibratory part to move laterally therewith, and at least one drive pawl engaging on the periphery of the stepping wheel and mounted in substantially fixed position with respect to the frame, said wheel being near the second bearing, and a pinion on the arbor near the first bearing for engagement with a train of wheels, said drive pawl being off the perpendicular to the axis of the arbor so that vibration of the second bearing and engagement of the pawl with the wheel will impart turning motion to the latter, and a detaining pawl on the wheel acting in a direction perpendicular to that of the drive pawl, and mounted in a fixed position relative to the frame, said bores being of increased diameter at at least one end thereof sufficient to permit the vibratory part and bearing therewith to move laterally without binding of the arbor end portions in the bores, said frame being provided with a work plate carrying the pawls and fork whereby the pawls, fork and plate constitute a unit of construction suitable for replacement on the frame.

2. In a clockwork as claimed in claim 1 said pawls having spring blades, and said plate being provided with Y 4 v fixed position slotted lugs to loosely receive outer ends of blades and the blades being cemented onto said lugs.

References Cited FOREIGN PATENTS 343,912 6/1960 Germany. 1,200,032 12/1959 France.

RICHARD B. WILKINSON, Primary Examiner 10 EDITH C. SIMMONS, Assistant Examiner US. Cl. X.R. 

